You can find the volume with or without calc. Which do you wanna do?.

Volume indicates 3-D. I suppose you mean a cylindrical tank of radius 13/20 and length 21/10?.

Here's the calc method for the volume(shaded portion) of the cylindrical tank of radius 13/20 and length 21/10.

You can do it without by using the formula for the middle ordinate.

You are given the heighth of the segment, 1/5.

Solving, we see

Now, sub that into the formula for the segment of a circle:

This is the area of the segment, you need the shaded portion.

Multiply this by the length, 21/10.

You get 2.5154. Same as above